Jan 3 Getting to the Details

As it happens, I'm thinking of late of my two listening "areas" in the house and how I might upgrade the experience (of listening).
Downstairs, in one of the larger rooms of the home, I have a 2-channel system set up with a Mac Mini, a DAC, monoblock amplifiers, and of course, speakers. I have no headphone capability there. Upstairs, I use my computer and I have a set of bookshelf speakers, although more and more, I find myself listening via headphones.
This holiday, I received a new pair of headphones which immediately, with 0 hours on them, sounded more open and telling. They had a far more focused detail. They are very similar to my last pair, same manufacturer, just another step up in the line.
But the connections in my upstairs setup are far from ideal: I am taking the music from an analog headphone jack (mini jack), to an integrated amplifier, to the headphones. What I need is another digital to analog converter (DAC) to get more sparkle and detail about of the music.
So, I began looking to replace the downstairs DAC. My desire there is to eliminate the preamp altogether, and drive the amplifiers with a DAC that includes a digital preamp function. While I search for the perfect solution, I've moved the downstairs DAC upstairs, and am still breaking-in the new headphones.
All I can say is—I am once again re-discovering my music collection. The amount of detail I am getting out of this setup is incredible. You can hear details you never knew existed. At the same time, I'm discovering my iTunes library was slowly becoming corrupted. I rebuilt the library (by eliminating the iTunes Library file, and then re-importing the iTunes Library.xml file), and as I listen, I'm amazed.
I am also finding some CDs that were never "upgraded" to re-encodes at lossless or 320kbits (remnants of my original ripping project in 2001 at 160kbits). Maintaining a library of music on the computer is efficient and fun, but it also requires some maintenance from time to time.